alps vs RainLoop

A side-by-side comparison of two self-hosted mail servers options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
FeaturealpsRainLoop
Deploy effortRead-the-docs projectUnder-an-hour setup
StatusActively maintainedArchived
CategoryMail ServersMail Servers
LicenseMITAGPL-3.0
LanguageGoPHP
Setup difficultyMediumEasy
Min. RAM64 MB128 MB
Deploymentbinary, sourcedocker, bare-metal, source
GitHub stars★ 700★ 4,114
First released20202013
ReplacesGmailGmail, Outlook Web

What are alps and RainLoop?

alps

alps is a minimal webmail client that connects to IMAP and SMTP servers, designed to be lightweight and extensible. It is developed by the team behind the SourceHut mail infrastructure.

  • Minimal webmail interface
  • IMAP and SMTP support
  • Plugin system
  • No database required

RainLoop

RainLoop is a fast, simple webmail client with a modern interface that works with any IMAP and SMTP server. It stores no email data itself, acting as a thin client.

  • Modern, responsive UI
  • No database required
  • Multi-account support
  • Works with any IMAP server

alps vs RainLoop: key differences

The biggest difference is maintenance: RainLoop's repository is archived and no longer developed, while alps is actively maintained. Alps is written in Go, while RainLoop is built with PHP. Licensing differs — MIT for alps versus AGPL-3.0 for RainLoop. Alps is the lighter option, starting around 64 MB of RAM against 128 MB for RainLoop. RainLoop is the more established project (first released 2013), while alps arrived in 2020. RainLoop has the considerably larger community, at 4,114 GitHub stars versus 700. RainLoop lists first-class Docker deployment; alps does not.

Why pick each one

Choose alps if…

  • Released under the MIT license
  • Written in Go
  • Tiny footprint — runs in 64 MB RAM
alps details

Choose RainLoop if…

  • Released under the AGPL-3.0 license
  • Easy to set up — beginner-friendly
  • First-class Docker support for quick deployment
  • Active community (4.1k GitHub stars)

Watch out for

  • Development largely stalled
  • SnappyMail is the active fork
RainLoop details

Frequently asked questions

Is alps or RainLoop better?

RainLoop is the stronger all-round pick: it has both the larger community and the simpler easy setup. Consider RainLoop if its specific feature set fits your needs better.

Are alps and RainLoop free and open-source?

Yes. alps is licensed under MIT and RainLoop under AGPL-3.0. Both can be self-hosted at no software cost.

Can I run alps and RainLoop with Docker?

alps: check the project docs for container support. RainLoop: yes.

Which is lighter on resources, alps or RainLoop?

alps has the smaller minimum footprint at 64 MB of RAM, compared to about 128 MB for RainLoop. Real-world usage depends on library size, user count, and enabled features.

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